The US embassy in Oslo was hit by an explosion early on Sunday, causing minor damage but no injuries, Norwegian police said.
A loud blast was heard near the embassy compound in western Oslo at around 1 a.m., and smoke was seen rising from the compound, eyewitnesses told local media.
"We've determined that an explosion hit the American embassy," police spokesperson Mikael Dellemyr told public broadcaster NRK, adding that the blast occurred at the entry to the consular section.
It was not immediately clear what caused the blast or who was involved, the Oslo police department said in a separate statement.
"The police are in a dialog with the embassy, and there are no reports of any injured persons," the statement said.
Local witnesses share what they've seen
Police are currently searching for the person responsible for the explosion.
Witnesses told local media outlet Verdens Gang (VG) that a canine unit, a drone, and helicopter are among the resources being used at the scene, as well as the police's bomb squad and forensic teams.
“I was sitting watching TV when there was a bang and the whole house shook,” VG quoted a local as saying.
A second local added that the explosion had woken them up, and that they had seen "heavy smoke coming from the embassy.”